(1) Field of the Invention
This invention generally relates to a method and an apparatus for balancing and more particularly to a method and to an apparatus for balancing a rotating machine tool and/or rotating/moving machine tool assembly.
(2) Background of the Invention
Machine tool assemblies are used to create and/or to form various parts, products, and other types of entities and/or apparatuses. Particularly, these apparatuses include tools which are usually and removably placed, by means of a tool holder, upon a rotating or moving spindle and which are adapted to engage a workpiece or other apparatus and to engagingly form the workpiece into a desired shape and size. While these machine tool assemblies adequately create the desired parts, products, and/or other entities they are prone to imbalance failure and/or imbalance error. Hence, the precision and reliability of these relatively high-speed machine tool assemblies is limited by the imbalance which exists and/or arises as the assembly is used (e.g. as the tool is engaging rotated and/or moved against the workpiece). Similar types of unbalance or imbalance difficulties arise in the rotation and the utilization of relatively high-speed turbomachinery which is used in a variety of manufacturing and electrical power generation facilities and which causes the loss of significant revenues if xe2x80x9cshut downxe2x80x9d and/or disabled for even a relatively brief period of time.
Some balancing devices have been created and utilized in order to overcome these imbalance difficulties. While somewhat effective, these prior balancing devices and methodologies suffered from various drawbacks. For example and without limitation, many of these prior balancers required that the tool assembly and/or rotating machinery be stopped or xe2x80x9cinterruptedxe2x80x9d before a balance was achieved. This xe2x80x9cinterruptionxe2x80x9d or xe2x80x9coff linexe2x80x9d balance was and remains relatively costly and highly inefficient. Some of the other prior balancing devices and methodologies experienced and/or caused a relatively high, although oftentimes temporary, increase in the overall vibration or imbalance level as the balance xe2x80x9ccorrectionxe2x80x9d was implemented. This transitory high vibration level was usually caused by the movement of the balancing portion of the assembly to a new balancing position and oftentimes caused the tooling assembly to be imprecise and to fail even before overall balance was achieved. The very act of balancing the assembly causes the assembly to fail or perform in an undesirable manner. Further, many of these prior balancers did not and do not adjust the imbalancing xe2x80x9cthresholdsxe2x80x9d (e.g. the vibration values at which balancing was and/or is to begin and end) during the xe2x80x9cworking lifexe2x80x9d and for various speeds of the machine. Hence, as the machine (tooling assembly) ages and as the machine and/or tooling assembly employs a variety of speeds its needs for balancing changes. Unfortunately, these new and different balancing needs were not and are not properly reflected by these prior deployed balancer assemblies.
There is therefore a need for a method and a balancing apparatus to allow for the relatively efficient balancing of a machine tool assembly, a relatively high-speed turbomachine assembly, or virtually any other rotating and/or moving machine and/or apparatus and which substantially prevents temporary vibration level increases during balancing and which allows balancing thresholds to be dynamically modified over the xe2x80x9cworking lifexe2x80x9d of the machine. Applicant""s invention addresses these needs and these aforedescribed drawbacks of these prior art balancing devices and methodologies in a new and novel fashion. Importantly, Applicant""s invention is not limited to the balancing of a machine tool assembly. Rather, Applicant""s invention is directed to the balance of any moving and/or rotating member.
It is a first object of the invention to provide a method and an apparatus for balancing.
It is a second object of the invention to provide a method and an apparatus for balancing which overcomes some or all of the various drawbacks of the prior balancing apparatuses and methodologies, including for example and without limitation, those which have been previously delineated above.
It is a third object of the invention to provide a method and an apparatus for balancing which overcomes the various drawbacks associated with prior balancing apparatuses and methodologies and which allows for the dynamic balancing of a tool assembly and/or other types of rotating machinery and apparatuses.
According to a first aspect of the present invention a balancer is provided. The balancer, according to this first aspect of the present invention, includes a balancer to selectively balance unbalance in a rotating tool assembly; and control means, connected to the balancer for causing said balancer to calculate an influence coefficient of the rotating tool assembly and to thereafter selectively balance the rotating tool assembly by the movement of the balancer, movement being defined by said calculated influence coefficient.
According to a second aspect of the present invention a balancer is provided. The balancer includes a balancing means to selectively balance a rotating tool assembly; and control means, coupled to said balancing means, for dynamically calculating vibration levels necessary for said balancing to begin and to end.
Further objects, features, and advantages of the present invention will become apparent from a consideration of the following detailed description of the preferred embodiment of the invention, the claims, and the attached drawings.
According to a third aspect of the invention, a balancer methodology is provided. This methodology includes the steps of a method of balancing a tool assembly by selectively employing a balance weight correction to said tool assembly, said method comprising the steps of employing a first balance weight correction to said tool assembly, measuring an amount of vibration associated with said balance tool assembly, estimating an influence coefficient value of said tool assembly, dividing said measured amount of vibration by said estimate influence coefficient thereby creating a certain value; multiplying said certain value by a gain parameter value, thereby creating a second certain value and subtracting said second certain value from said first balance weight correction, thereby creating a new balance weight correction and applying said new balance weight connection to said tool assembly.
According to a fourth aspect of the present invention, a balancer is provided which substantially reduces and/or eliminates transitory vibration increases.
Further objects, features and advantages of the present invention will become apparent from a consideration of the following detailed description of the preferred embodiment of the invention, these included and subjoined claims and the attached drawing.